Particle beam microscopes, such as electron beam microscopes or ion beam microscopes, are complex technical systems which are adjusted for optimum operation. One aspect of the adjustment of particle beam microscopes relates to the adjustment of the particle beam that is directed at the object to be examined relative to the objective lens with which the particle beam is focused on the object. Since the effect of imaging aberrations of the objective lens on the particle beam increases with the distance at which trajectories of the particles passing through the objective lens are situated from a main axis of the objective lens, it is desirable to centre the particle beam passing through the objective lens relative to the main axis. To this end, the particle beam microscope includes a beam adjustment device, which is arranged between the particle source for producing the particle beam and the objective lens and which is set such that it steers or selects the particle beam in a manner such that it passes through the objective lens in a centred fashion with respect to the main axis thereof. Determining the setting of the beam adjustment device that is involved herefor is typically performed in a separate method for adjusting the particle beam microscope in order to improve the efficiency of the particle beam microscope.
A conventional method for this purpose is known from EP 2 309 530 B1. In this conventional method (cf. FIG. 2 of EP 2 309 530 B1), a first image is recorded in a first setting of the beam adjustment device and a first setting of the objective lens. Next, a second image is recorded in the first setting of the beam adjustment device and a second setting of the objective lens. Next, a third image is recorded in a second setting of the beam adjustment device and the first setting of the objective lens. Next, a fourth image is recorded in the second setting of the beam adjustment device and the second setting of the objective lens. Due to the different settings, the four recorded images are displaced relative to one another. Corresponding displacements can be determined by analysing the images, provided the imaged object is sufficiently structured. An optimized setting of the beam adjustment device is calculated from the ascertained displacements. Using this optimized setting of the beam adjustment device and the first setting of the objective lens, high-quality images are then recorded.